Tabbles - Tabbles use tags to organize and find files along with your colleagues.
PracticePanther - PracticePanther offers CRM, invoicing, time tracking and communication solutions for law firms.
TagSpaces - TagSpaces is an open source platform for personal data management. With TagSpaces you can manage and organize the files on your laptop, tablet or smart phone.
MyCase - Practice More, Manage Less.
Elyse - The free version allows up to 30 tags.
Clio - Clio provides a full suite of web-based practice management tools targeted specifically at the administrative needs of sole practitioners and small firms.