There are many drawing tool. And it is difficult to choice one from such drawing set. Because there are many different features. Several years ago, I used OmmniGraffle (https://www.omnigroup.com/omnigraffle) It is also good tool for drawing. Because OmmniGraffle has many pre-provided object not only UML diagram but also room-design, circuits-design, chemical diagram, etc, etc..... And ommnigraffle has good and easy to use UI. So, it is not so difficult to drawing diagram as me who is awkward. (^_^ ;;;) However, it is not easy to share data with several computers.You need several installation of ommigraffle onto individual mac, and you need to share your graph data using some way as using e-mail, network storages, dropbox, box.com, or some other way. If you forget to make data onto such storage, then you need to remake from zero. Recently (this 3 - 4 years), I switch to use Lucidchart. Lucidchart has more simple interface and objects than ommnigraffle. So, it is much easy to use. T...