Thanks for your feedback! You can create sibling tasks using the Enter-key and subtasks with Tab. Tablet: Depending on what tablet you have the web-version might work but we also plan to build native apps.

You're completely right and in fact all URLs where your login credentials are transfered (login, signup, change password) are guaranteed to be SSL regardless of which plan you're on.

If SSL is too expensive for the Basic plan, consider dropping it altogether, or increasing it to EUR 9.95. You can also slash the free plan in half (1 project, 5 MB, 50 tasks) to encourage people to move on to paid; one project is more than enough to decide if the tool is for you.

I can't help thinking the github model might work here: publicly viewable mindmaps are free and you pay to restrict access to specific signed in users. Privacy is a better selling point than security, and some publicly shared mindmaps will generate backlinks.

You should also serve the pages on which the login/signup/changepassword forms are over SSL.

Things like login, signup, change password, ... always use SSL. In fact, currently everything else runs over SSL as well (even if you access the site over http you're redirected to https), it's just that in the higher tiers you are guaranteed that this will never change in the future.

Edit: Maybe I should add that I'm the developer of Subtask :)

It can be used as a mindmapping-tool, yes. However, it's actually more a project management tool than a mindmaping-tool, so some features like change the color of a branch are not available but you get all those PM features instead (like a calendar, comments, file attachments etc).