material.io is a free, no trick, easy grab, palette tool that will allow you compose your color harmony for Android and iOS in a very simplistic way.
This website is based on Material Design, which is a design language developed by Google. Very popular across the board.
https://material.io/resources/color here you may find a large array of colors and easily generate primaryColor, primaryLightColor, primaryDarkColor, secondaryColor, primaryTextColor, etc.
On top of that, it will allow you to download straightaway a colors.xml or colors.xml file with all the constants well defined, which is pretty convenient. Ready to drop into your Android Studio or XCode project.
It’s sometime confusing for new developers
(or rather new Watch iOS developers) to find exactly where to set the Watch
Icons. Well… it’s actually pretty simple.
It may be a bit unclear, because if you use a standard XCode template App, you may find two Assets.xcassets. The first would be under the WatchKit App and the second one under the Watch Kit Extension, usually where you insert your code logic.
Submissions for mobile apps for iOS are subject to approval by Apple’s App Review team, as outlined in the SDK agreement, for basic reliability testing and other analysis, before being published on the App Store.
Applications may still be distributed ad hoc if they are rejected, by the author manually submitting a request to Apple to license the application to individual iPhones, although Apple may withdraw the ability for authors to do this at a later date.