I've used greenaddress previously and I feel that the concept was somewhat okay. Personally, I feel that it doesn't provide much more security than a wallet without a 2FA enabled. Now to the negative part:
Their Android app was nothing short of confusing and buggy. There was this one time where I've sent 0.044BTC to an address in a greenaddress wallet I've created on my Android app. I was certain that I have done the 2FA correctly and I didn't set any emails. IIRC, it crashed and closed after I've created the wallet. I wasn't given any warnings about it. When I tried to send the funds, the 2FA was incorrect and I was frustrated as hell. Thinking that I can get my funds back with their timelock function, I decided to wait. However, I can't send any of the files with the fact that there is no email set with the wallet. It's $500 in today's value and its terrible to see it stuck there. Their support wasn't helpful at all.
In short, stay away from Greenaddress.it. Good idea but terrible execution.
Ah, I see. I was starting to believe that all those reviewers posting negative ratings on the Play Store were just not technically savvy and were simply misusing the wallet and losing their bitcoins in that way. It is good to hear from a fellow forum member whom I believe has much more knowledge of the scene and of Bitcoin itself. I will take your advice and avoid them at all cost in that case. On a similar note, is there any wallet that is actually good on Android in your opinion? I have been using blockchain.info as my sort of portable wallet, but I would be more than willing to try out something better.