It's very likely that it will still just be a "Send" button. Channel management and all that will actually be handled by the software automatically. You put money into your LN wallet, and it will use that to open and close channels automatically. So when you want to send Bitcoin to someone, your LN wallet will have established several channels. It will also determine an optimal route and do everything automatically for you. There's no need for you to manually open and close channels yourself; the software will handle all of that for you.
That seems to be the approach that HTLC.me is following. It's fine with testnet coins, but I'm still not sure how to feel about mainnet on-chain transactions taking place without user interaction. I guess in the end people will have multiple implementations to choose from, depending on how much convenience vs control they want.
Is there some kind of guide for the eclair testnet wallet? I downloaded it on my phone but have no idea what exactly am i supposed to do with this. Do I get testnet currency from some faucet?
Yep, just get testnet bitcoins from one of the faucets. Here for example:
https://testnet.manu.backend.hamburg/faucetIn Eclair swipe to the leftmost screen for your testnet address (starts with 2...) and once you got some coins swipe to the rightmost screen and open a new channel by tapping on the big green plus button. Autoconnect should suffice for the first try.
Once the connection is confirmed (ie. the channel state says "normal") you can send lightning transactions from the main screen by scanning payment requests -- eg. on yalls.org or by creating a payment request for yourself on the HTLC.me web wallet.