1) Arrange crackers on a plate.
2) Spread thin layer of creme fraiche on each cracker.
3) Thinly slice avocados and green apples. Arrange one of each on top of each cracker.
4) Place pieces of smoked salmon on top of apple and avocado.
5) Pepper to taste. Add capers if you'd like.
6) Squeeze fresh lemon over all crackers.
7) Serve immediately!