[Ethereum] Can the Android Metamask Extension be used with DApps

Your ether balance is 0, which is insufficient to pay the fee for the transaction you're doing. All transactions in Ethereum require gas, and ether is used to pay for that gas. Transfer some ether into that account and try again. (You should need less than a dollar's worth of ether.)

The code for MetaMask or seems to be available here at GitHub.

If code is in github means product is safe & secure?. Well I wan to clarify 2 points:

1. Attacker will analise code, if there any loop holes in the code. Attacker will try to enter from that hole to hack. This is happening more frequent attacks in crypto world[major attacks using this way]. I am not against open source.
2. Good side every one know[transparency] whats going on inside product/tool.

As per @danfinlay Today, MetaMask is indeed a "hot" wallet, in that you use it on a computer connected to the internet. This is usually considered less secure, because if a machine is on the internet, it could be accessed remotely, and keys could be stolen.

For more details refer below links: https://www.reddit.com/r/ethereum/comments/6j7445/how_secure_is_metamask/ https://steemit.com/eos/@sandwich/how-to-move-from-metamask-to-myetherwallet https://hackernoon.com/how-one-hacker-stole-thousands-of-dollars-worth-of-cryptocurrency-with-a-classic-code-injection-a3aba5d2bff0