Sortd - Rated the #1 App for Gmail
scr.im - Don't share your email on public sites.
KanbanMail - A Kanban board for your emails.
Spamty - Spamty is a web service to encrypt an email address and share it on the internet.
Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.
reCAPTCHA - reCAPTCHA is a free security service that protects your websites from spam and abuse.