I think that dissection lab is the best alternative to live dissections. It offers students the opportunity to virtually dissect a frog (free), rat, earthworm, cockroach, starfish, shark and pigeon.
The Good:
- Free (in app purchases)
- Interactive
- Engaging
- Includes a lot of extra information (taxonomy, habitat, life cycle, etc)
- includes assignments and quizzes
- realistic
The Bad:
- In app purchases (from $1.99 -$14.99 per additional animal)
- Perfect (there is no way to make a mistake and correct it)
- overly guided
- Possible for students to go too fast through dissection, and be bored for the rest of class

Overall, the app is well laid out, and intuitive. I would use this app as a dissection alternative in my classroom – perhaps on a class iPad.