The Perseus Project also has a vast amount of useful resources for the Latinist; in addition to hypertexts and translations (of Seneca's Medea, and of many other Latin and Greek works), see Allen and Greenough's Latin Grammar, and a searchable edition of Lewis & Short, the best one-volume Latin dictionary.

But you can have an electronic version of Lewis and Short for your own use. It's part of the database of Diogenes, a freeware application by Peter Heslin for searching the TLG and PHI disks. If you don't know what those are, don't worry about it. The upshot is that you can use Diogenes as a standalone dictionary program, by far the best one out there (for Latin or for Greek: the complete dataset of LSJ is included as well).

https://d.iogen.es/d/download.html

https://latin-words.com

There are some great free dictionary and grammar programs for iOS (e.g. Protagoras, Grammaticus, and Logeion), but these, unfortunately, don't seem to have crossed over to the Android marketplace yet.

Again for iOS/iPadOS: Bellerophon is a reading program by Adrian Packel that is essentially the Perseus Project on your mobile device: texts, translations, hyperlinked parsing and dictionary functions. (Added 2/26/24: Bellerophon is not quite as useful in recent iterations of iOS/iPadOS, but still has a large library and an effective parsing function.)

https://apps.apple.com/us/developer/adrian-packel/id517244370

There's a Latin parser for Android devices by Water Shandruk. Not being an Android user, I have no idea how good it is, but here's the link.

https://download.cnet.com/latin-parser/3000-20414_4-75945591.html

There are increasing numbers of for-pay options for mobile platforms (iOS and Android). I'm not inclined to link to these, but if you want to have a conversation about the ups and downs of them, feel free to raise the question in or out of class.