Thumbnaily is free because it is currently still in beta and under development. The beta period is free to collect more feedback from users.
When the Beta ends, Thumbnaily will have paid plans that unlock extra features not available to free users. You can continue using Thumbnaily for free with limitations.
I try to add features as fast as possible but I am a solo developer working nights and weekends besides my regular job. Please keep this in mind.
You can use the chat on the bottom right, send me a tweet at Thumbnaily on Twitter or send me an email at firstname.lastname@example.org