If you want to have access to funds from anywhere, just use an online exchange, or even a bitcoin casino wallet!
If you want to have acces to the same wallet from several places, just import the keys to whatever wallet you want to use on a particular device.
Using online exchange or casino to store your BTC is even more dangerous than a service dedicated to storing Bitcoins. There were alot of cases of exchange and casino owners running away with your BTC compared to dedicated wallet services, although there is still risk.If you want to have acces to the same wallet from several places, just import the keys to whatever wallet you want to use on a particular device.
It depends which one you use for example I would trust dooglus and just dice as much as blockchain.info in terms of security of your Bitcoins and storage procedures.
The problem with the investor feature is the variance so your coins can be eaten or grow a bit depending on when you deposit although it tends to grow in the long term but 1 Big Whale will mean it takes a while to recover that initial loss
Good old house edge