Skala Preview is free, and works with Sketch, for iOS and Android previews.

https://bjango.com/mac/skalapreview/

Disclaimer: I work on Skala Preview. Feel free to ask any questions.

Sketch Mirror is a pain. I design apps for mobile devices on a daily basis and i need it to check distances, colors and readability. I wrote Bohemian several times and had a ton of feature and bug request but they don't listen it isn't on their priority list for sketch i asume which is sad. Things that bug me the most:

1. Constantly crashing of the app
2. Multitasking results in Crash
3. It syncs all Artboards which is stupid
4. No Prototyping with cloud synced sketch files
5. The "Follow Artboard Feature" is bad because it won't work with heavy files properly. You can either "follow" artboards or choose them yourself, do that with 5 pages each 50 artboards. Try to find the right one.
6. You cannot lock artboards so when i jump to the next artboard to copy an object it will load the new Artboard.
7. You cannot save the artboards in the app
8. Performance issues sometime it takes a while to see changes, which can result in restarting the app because it freezed and you didn't know.

I could go further but it hurts so much...

As long as I just watch and click through the prototype, everything works fine for me. As soon as there is some change, Sketch Mirror crashes and needs to be restarted. Ultra - annoying.

I've never successfully used it for its intended purpose. That's how bad it is.

Every once in a while I'll reinstall it and give it a go, but it will only load pixelated versions of my designs…or a black screen. No amount of fiddling with the wifi has ever worked, nor has reinstallation. I've tried it on three different devices with no luck.

For Sketch being such a great – and integral – part of my workflow, the companion app is a huge disappointment.

Use everyday and is a pain -.-

Agreed, I feel like it used to be better than it was but likewise I contantly experience crashing and freezing, as well as really laggy response and issues with the design scaling to the device

Mirror is a dumpster fire, and confusingly, it seems to have only gotten worse over the last couple years. I wish I didn’t have to use an app that I have to force quit 20+ times a day. It constantly bugs out and loses connection or randomly freezes, requiring quitting the app, disconnecting/reconnecting the phone, etc.

WiFi and USB modes are equally terrible.

I wouldn't resort to hyperbole, but the app is kinda problematic for me.

Firstly, I can never get it to connect to Wi-fi without first connecting via cable. After it connects to Wi-Fi once, it works fine...until,

Secondly, whether the artboard I'm looking at will update is a dice roll at best.

Lastly, I find myself opening it 2-3 times as much as I should, as quitting and restarting the app seems to be the only way to get it to refresh sometimes.

I still use it though. When it works, it definitely helps. But, yeah, it's problematic. I guess I don't sit around cursing its name, is all.

Had very little success using this. Way back in the day when Sketch just arrived in the design scene, I vaguely remember it being quite good...

I have the same issues and have for a while. It freezes and have to restart it very often.

Sketch Mirror: 30% of the time it works every time.

When it works it's good, but I've found since Sketch 52 its far slower to render, even over USB. I emailed support and they were basically useless and told me to reinstall it, which I did, and it makes no difference.

I agree but it's not as flaky as Adobe Preview was... I found if you turn auto update artboard it works pretty well with fewer issues.

But it isn't the point I know haha.