Flexiglass App Reviews

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Crashes occasionally (Review updated for 2018, version 1.6.2), no updates since 2015

Feb 2018 update: 2017 15 inch Macbook pro with touch bar. Flexiglass continues to crash with certain applications (it will always crash with microsoft one note when I try to realign the window). Certain applications do not dock with flexiglass. I've been using flexiglass for about 3 weeks now (i used the version prior to this one) and have been using this latest version for the past 3 days. So far, no problems whatsoever. I'm using this on my macbook air and the app runs seamlessly. Flexiglass has worked with all my programs so far (ms office, chrome, iTunes, spottify, adobe reader specifically on a day to day basis). The only thing I can complain about is that, when trying to dock the windows (side by side or on corners) theres a half second lag where the window highlights what its going to do (ex: dock in a corner) before it actually docks itself. This lag is only apparent when you use a touch pad such as the one on my air. When using a mouse, the lag goes away and the windows instantly dock. Overall, I love this app. I came from windows 7 and i loved docking my windows because I often times read one file and type onto another simultaneously. This app brings that functionality over to lion (i have no idea why it isn't native), it was the one thing that I thought windows 7 had over lion. But now I can't complain about my mac anymore = ) Update: There is no more window docking lag in version 1.5!!! Still have not had any problems with this app.

Rock star app!

If you do any type of writing, reading, or work with any type of documents or applications where you need to compare multiple versions simultaneously and need a way to quickly resize the application window or document windows — Flexiglass is your app. Apple has JUST created the side-by-side view in El Capitan — boring — because you don’t always view side-by-side. Flexiglass has been doing split views for years and with a few key strokes you ALSO get TOP & BOTTOM split as well as a way to QUARTER split the apps/windwos into the four corners of your screen display. This is such a rock star app — I love it. You’ll love it too!

Buggy & Expensive

I bought Flexiglass to allow for a very convenient way to move and resize windows. It implements the functionality very poorly. First, moving doesn't work on all types of windows, e.g., System Preferences. Second, resizing Terminal and similar text-based applications also selects text while resizing. How hard is it to do one thing and then do it right?! After getting in touch with the support, the only thing they mentioned is "we hope to fix it in the future". Very unsatsifying. This is by no means a $10 app, given the buggy implementation.

Couldn’t imagine life without it.

Love Flexiglass so much. A must have for all advanced users. Most underrated app on the Mac App Store. Thank you, Nulana LTD.

El Capitan

Thank you for the super fast update. I was wondering why Flexi wasn’t working last night!

The best app I ever bought!

I have literally never taken the time to write up a review, but in this instance I feel very compelled to! Since switching from PC to apple I was struggling with the functionality of reorganizing my open windows, especially since I often have multiple documents / webpages open at a time. As soon as I downloaded flexiglass, those problems were history! It is incredibly intuitive to use, with very little required for the setup. Establishing keyboard shortcuts is fast and simple, and now my mac is far easier to maneuver than my former PC ever could be. Definitely recommend, $10 is nothing for this app!

Does not work in multiple user IMACs

Buy Sizeup instead. . Does the same thing but not limited to single users. I bought Flexiglass several years ago. Great functionality in single user mode. But if you have multiusers in one computer it crashes as soon as you switch users. I just bought Sizeup. Does the same thing but no longer limited. Too bad Flexiglass doesn’t keep up.

A life-saving app

This app saves my life! I am a heavy user with lots of windows open and it is imperative to me to be able to organize windows so that I can see multiple sources of information at once. Flexiglass does have stability issues at times but I am giving it 5 stars for how much it simplifies my use of MacOS.

Activates when resizing

I’ve used this app for about 6 months. It worked well, but I noticed that when I resize a window to the edge of the screen, flexiglass activates and then moves the window there. I contacted support about it, but they never bothered to fix it. I’m going to try out Window Magnet which currently has a 5 star rating.

Works but Crashes Sometimes

This app works as advertised when it doesn’t crash. It doesn’t crash frequently, but it does it often enough that you will notice it. Luckily, it’s a tiny app so re-starting it is not that big of a deal. I love the drop down menu and how you can arrange the windows on the preset layouts. I also love the shortcut keys. I love you can double click the title bar to maximize and right click the green orb to maximize. I especially like the right-click the red orb to close the application window. I disable the moving and resizing feature. I found that conflicts with some built-in Mavericks functionality. Other than that, it’s a great little app and you will find it very useful.

When I resize the window, I can feel the lag.

Same as title.

Love it! But...

I’ve loved this app since I got it… Why OS X doesn’t do it by default is beyond me. But… it doesn’t work now that I’m on Mavericks! Hopefully there’s an update soon because I’m really missing being able to throw my windows around and having them fill the screen quickly.

Everything I need

Snap features by dragging and keyboard shortcuts is exactly what I wanted. Well worth $10

Neglected, uses “significant energy”.

This was an awesome app for a while, but it seems to be neglected. In Mavericks’ "energy shaming" it shows Flexiglass uses “significant energy”. I expect MAS app devs to run beta OSX builds and fix obvious issues such as this.

Uses Discrete Graphics

I was a big fan of Flexiglass and now for somereason it has started to use the Discrete Graphics on my rMBP. Why is that? Why does it need to use Discrete Graphics ro run this simple application, there is no need for it. It can run perfectly fine on macbooks without Discrete Graphics, so why run it on Discrete Graphics on rMBP 15”. For now, I have stopped using this and started using Divvy and told my friends and family to switch as well. Please resolve this issue!

Does Not Work with TotalFinder

The features of flexiglass are great, but when software does work with flexiglass it becomes a handicap. I use an app called TotalFinder and flexiglass does not work with this program. Also my Adobe CS6 does work as well. I stopped using this app and purchased a program called Cinch for the Windows 7 like snap and it works with TotalFinder. If you've never seen TotalFinder, check it out! It creates chrome like tabs and split views in Finder!

Great app!

Only thing it could improve on is being able to customize the size from left to right. So instead of dragging to the left and automatically it will go to 50% you could customize it to be 75% left and 25% right. Not a huge issue and still well worth $10.

Great in Theory

App works great on a computer with only one user account. It continually returns an "instance checker error" on computers with multiple usser accounts though. It been like this for a long time which is lame.

Love resizing windows!!

Since i recently migrated from windows, i was frustrated with some of the features i didnt have in mac. Thanks to flexiglass, i can finally manupulate the windows. The maximize button works perfectly, but the red X doesnot quit the application as described. i hope the fix it soon.

Great, except for photoshop Cs6

Great except with the new adobe cs6 line. Most people won't have this problem (since they don't have Photoshop), but none of the photohsop products work with flexiglass. Please fix.

Great idea with issues

I love the functionality with this app, however it eats ram and resources over time. When you start the app it is using about 20MB, but within a day or so it can be much more. I just checked activity monitor and within 2 days it was now using 147 MB. This to me says it is a poorly coded app, or it is sneaky and collecting information.


This is great for window management. I'd only suggest having a 3/4 view as well. But it's perfect as is and is very stable.

Thank You!

This App is amazing!!! The one thing that Windows 7 had over apple's OS, you can get with this app. I mainly got it for the split screen function that allows you to easily set to applications to use half the screen. Thank you, It does have some problems occossionally where I can't bring up the dock. Other than that works great. And thank you for fixing the problem with Chrome

This application is good, when it works

For what it does this app is great, It works with no fuss, but it has some issues with mutliples monitors and for what ever reason chrome 17 and above. I wish they would fix it but they dont have a good support system on their website. Anyways. Still a good product.

Overall Good

Overall, the app is quite nice/usefull. It works exactly as advertised on a single screen, and I am very happy with it. It is, however, quite glitchy when used with a dual-screen setup. It puts the window in a different corner/area from the one that I try to drag it to, and I can't get it to snap to certain areas. If this bug gets fixed, then I will give it five.

This app is great

Really like this app. Please add Exceptions to Layouts.

great except when it misses clicks

The newest version sometimes ignores mouse clicks when i try to change windows in Lion. This happened occasionally under Snow Leopard but is more quite frequent under Lion, which is a signifiacnt problem. I've stopped using it until this issue is fixed.

Lion issues?

I really want to love this app b/c it does exactly what I'm wanting, but it's super buggy on Lion with my Magic Trackpad. It seems to mess with transparency as well other issues like moving windows by grabbing their top bar doesn't work when I have it running. For now I've shut it down, hoping that an updated version for Lion comes out soon...

Big issues with OSX Lion

When using with my Magic trackpad in OSX Lion, a single click very ofter acts like a click and hold. This only happens when I have Flexiglass running. Worked great with previous versions, but this is way to buggy. Had to stop using it all together.


Flexiglass removed the forward and back trackpad feature in safari. (eg If you use two fingers horizontally to go back or forward through web pages…you can't!)

interferes with some controls

I've been having strange problems with xcode and perforce not responding to some button clicks. When I close flexiglass, the problem goes away. Can't recommend.


I have been looking for the best Mac window manager for a couple of years and this is it. There are plenty of alternatives to Flexiglass but this works beautifully and seamlessly across the screen. Cinch used to be my favorite but always felt clunky and slow. I only have one question… What is the amazing song on the Nulana website being played in the Flexiglass demo video?


I LOVE the features this has, and IF IT WORKED properly, this would be a MUST HAVE program! BUT, this program has NEVER worked right for me! It works for a little bit, then all of a sudden I'm using Google Chrome and I try to open a new tab, or start typing in a URL, and Chrome completely locks up, and is unresponsive for a while.. UNLESS! Unless I go up and simply click once on the FlexiGlass Icon in the task bar at the top of the screen, and Chrome will INSTANTLY become un-frozen. PLEASE, PLEASE FIX THIS HUGE BUG!!! COME ON!

why doesn't Lion just naturally do all this?

I've been using Flexiglass with Lion since a previous application I had stopped working with the update to Lion (something ancient and not available anymore). Anyway, I've had pretty good luck with it. Works far smoother than Cinch and does much more than Window Magnet (I've been shopping around). On my big screen iMac, it's done a wonderful job with my trackpad and has made life so much easier. On my macbook, the results are less dramatic, but still quite good. This loses a star, however, because it's not 100% consistent (but is >90%). Its biggest problematic areas are in the keyboard shortcuts which work off and on (but, frankly, I don't need/use them that much). I strongly recommend this app to everyone.

Still interferes with trackpad gestures in Lion

I was hoping this would have been fixed by now, but this latest version does not fix it. I had been using Flexiglass for a couple of months, before Lion was released. Under Snow Leopard, it worked great. I really like the ability to drag windows to the sides to automatically take half the space, and I use several of the other features as well. But I have been unable to use it since Lion came out… What I found was, when Flexiglass is active, many of my mouse clicks won't take. That is, I'll click a button, or even a web link, and I'll see the visual behavior on the screen showing the mouse-down event (e.g., the button will appear depressed), but that's it. I have to click a second time for the application to recognize the full mouse click. This happens sporadically, but I would estimate it happens about 30% of the time or more…so very frequently. I use a Trackpad, both embedded in my MacBook (Pro and Air), and an external track pad when docked to my large screen displays. The behavior is consistent with all of them, on both computers. If I kill Flexiglass, the normal behavior resumes. I'm certain now it is Flexiglass. Another clue, my Trackpad preferences set "Tap to click"… so I do not need to physically click the trackpad. I just tap lightly to get a button click. I'm guessing the Flexiglass testers do not have this set, because my guess is the problem is a conflict with Flexiglass and Tap-to-click. (Could be wrong.) FYI, I also have "Secondary Click" (with two fingers) checked, as well as "Look up" and "Three finger drag". I hope you can fix this soon. I miss the app.

Crashes on "Open at Login"

An app like this you'd expect to be able to have it Open at Login without a problem. Sad thing is it crashes every time I turn on my iMac! Still hasn't fixed crashes yet!


MacBookPro6,1 running OS X 10.6.8 The core functionality of this app is fantastic, however, constantly needing to shut it down and fire it up again to fix the horrendous "autodetection" bug is killing it's utility. The app has different settings based on whether you are using it with a standard mouse or the touchpad, and it claims to be able to detect which you're using. It cannot. Moreover, even when you disable this autodetection, it still gets stuck in touchpad mode. I would love to see this app in all it's glory, but for now i'm going back to Divvy + Moom.

Please FIX!!!

It used to work pretty well with Mac OS Snow Leopard, but now that i'm using Lion sometimes it works and sometimes it doesn't.

Potentially nice, but flawed

Siince upgrading to the current 1.3 version Flexiglass has caused numerous frozen windows and unresponsive menus, forcing a restart to correct them. Only after quitting Flexiglass did the problems disappear. It is a potentially nice app, somewhat more powerful than Divvy, but it causes too many problems to be useful.

Conflict with Outlook 2011

Something in the latest update causes Outlook 2011 to become so sluggish it's unusable. Quitting Flexiglass fixes the problem. Starting up Flexiglass causes the problem to reappear. Contacted via Twitter and now support, but haven't heard back yet.

Amazing Application

It is just incredible. I bet you save hours upon hours. It is incredibly useful from a single 11" MacBook Air, all the way up to a dual 30" Apple Cinema Mac Pro setup.

Great way to move and re-size windows fast and easily

Love this window-moving-window-resizing App. I like the option that highlights the window border with your favorite color. Nice! This App offers a lot of nice ways to handle moving and resizing. But for me, using an easy memory jingle Left-Move / Right-Size along with the Option key for both and the Left and Right mouse click makes moving and resizing a breeze. When I use the big TrackPad it becomes Thumb-Move / Pinky-Size: holding the Option for both actions, click and hold with the thumb and use my index to move, but really, almost feels like "tossing" that window where ever I want and when it's time to resize, pinky on the lower right side and index-finger making that window resize so fast. The best part of this App is that it's very responsive whether you mouse your windows or track pad them. To the developer a bow of gratitude.... m(_ _)m

The pain of moving and resizing is gone with this app.

I gave to this appp 5 stars. It worth it. I developed my self an app for Windows,"Desktop Organizer" and I was missing so baddly this features when I was working on Mac. Thank you. Ovidiu

Don't purchase version 1.0, but do purchase the next version

Con: It *almost* works. Several people here have already mentioned issues/bugs in 1.0. Myself, I'm plagued with the "snap to fullscreen" problem. I experience this about 9 times out of 10 whenever I use Flexiglass to move or resize, such that I don't do it any more. Basically the only functionality I can use right now is the right-click on the red button to close, which is nice, but I usually just command-q anyway, so it's not too helpful. Pro: The developer has been very responsive to my few comments on the feedback page of the website. I got a reply within 1 day telling me that this was a known bug in version 1.0 and that an upgrade had already been submitted to the apple store and was waiting approval. I have confidence that this will work itself out. My advice is to wait for a later version and then purchase. it looks promising, and if it decides to work as advertised, it's going to be a very useful tool.

Best App for management of Mac OS Windows!

I've been using it for almost two weeks now... Before flexiglass i used to use "cinch", and "sizeup". Trust me, go ahead and buy flexiglass, you'll save money and will be using a far better app than any other management window app. You can resize, maximize, move, close with a mouse, use trackpad multi-touch gestures, keybord shortcuts... The interface kind reminds me of NuKit (witch is awesome). Windows users will love this one!

It's great when it works, but . . .

There is one bug where widows get stuck in the full screen mode and no matter where you drag them, they will snap back into full screen. This is very frustrating and I would not recommend this App until the bug is fixed.

How about 1.0.2

This is perfect app and really does the job. One question for developer - on website I can see 1.0.2 so when on MAS?

Good app, serious problems with multiple monitors.

The app seems well designed and the features are quite nice and well thought out. It has one fatal flaw: every time your display configuration changes you must re-start the app, or else all sorts of incredibly obnoxious window size and position issues occur. This doesnt seem that bad until you consider a home/work laptop that has as many as three different monitor configurations in a single day. Hopefully they will resolve this in the next update.

Great! but..

great app but the icon on the dock is a little annoying. I like to keep my dock clean and uncluttered. I feel that if the icon for this app were to be at the top of the screen next to the time and battery icons it would be more pleasing to look at

Doesn’t work with multiple monitors

Dragging to any screen edge makes the window simply take up my whole second monitor, rendering half of this app’s core functionality worthless!

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