For example the word Retrica is a trademark.
However are you allowed to you something like Camtrica? I mean I don’t think Google Play Store would ban your app if you use that because it is not impersonation?
Haven’t tried it out but yes I think this will not ban you over the playstore ! I am afraid to give it a go so if you get any… then do let us all know about it !
I will try it out and I will let you know guys. First I am thinking of asking a lawyer but to be honest that won’t be a problem because I see many Angry Birds clones called Angry Cows etc. that is just an example. The companies cannot trademark something like angry or for example instagram I know one called Flipagram or Instatags so I think it should not be a problem.
They cannot, but Google might ban you anyway for something like Angry Cows - read the policies. You cannot immitate other apps.
I see many many apps with millions and millions of downloads that imitate other apps. ALso I contacted a lawyer and she said that Generic Words can be used at any time Generic Words are not a subject to trademark 
SO you can Use Angry doesn’t matter
You can use it without breaking law. But Google might decide you are breaking their policy (impersonation is most likely reason) and then you have no saying whatsoever. Camtrica seems safe though, it’s much different from Retrica. Make sure though your app doesn’t look exactly the same.
My game Jigsaw Puzzles Saga was banned from the EU stores for using the word “Saga”. King reported a lot of apps that were using “saga” and google complied.
We have a dedicated team of representatives on call24/7 to respond to inquiries and issues that may arise while using services rendered by us ( https://rankmywriter.com/masterpapers-com-review ). Communication channels are via a live chat feature, email, and telephone. We have a high response rate and ensure that each inquiry receives satisfactory answers.