Any Suggestions for Reliable/Secure Personal Training Software for In-Home Fitness Services?

I am interested in personal training software that is reliable and keeps client information secure. It would be nice to use it for administrative and practical purposes (client details, initial paperwork, assessments, reminders, billing, taxes, statistics, exercise library, training plans, video, client interaction options, etc). I’ve searched online and found multiple programs, but it would be helpful to get some of your feedback.

What software do you recommend and what features do you like most/least? How long have you been using the software? Any other comments or suggestions are appreciated.

Thank you!