Which wallet is good to store ERC 20 tokens for long time?
Desktop or Android based?
Myetherwallet is absolutely good and safe wallet for ethereum which is also allowing you to store all of your ERC20 tokens, that you can use to store your holdings for a long period of time, through the use of desktop and android phones.
Is myetherwallet available on Android platform?
I don't think so it is available if it is something on the android then it will be a scam wallet never ever store anything there then you will be scammed.
As i said earlier, you can use it through desktop and android phones, myetherwallet is not a downloadable wallet. And i'm sure that this wallet is pretty safe for storing your funds, unless you share your private key, it will surely scammed. And besides, you can use it wherever you like, unlike the desktop wallet that you can only use it to somewhere that desktop or laptop are available to use.