I love Practice Panther. It's affordable, customizable, and just plain wonderful. It's practice management, billing, tracking, and pretty much anything else you can think of. They also have a client portal which clients can access their invoices, files, and message you or upload docs to you...they can even fill out intakes or custom made forms on there. At first, I didn't think clients would use it much, but turns out, they love it! They have free trainings with an actual person and all that to explain how everything works. Would recommend it to anyone.