I use the Fertility Friend one too. It also has a password (optional) like the others. I like that it synchs with my account on the website so I can use either my phone or computer to enter the data.

ps. I don't think it's overly clunky... There's just a lot of data options to wade through, but the most common ones are at the top so you can ignore the rest if you don't want to use them. It's leaps and bounds ahead of their old app.