What are some alternatives?
When comparing Register to Vote and BTC18, you can also consider the following products
Vote.org - Everything you need to vote
ChartsMe - 27 strange questions to find your brain's political belief
VoteWithMe - Remind your friends to cast their vote 🗳️
Brigade - The world's first network for voters
We The People - Yik Yak for politics and much more for Election 2016
Votebox - Secure internet voting