Time to make a reference sheet!  
Filled in as we go.
 
1-6 =?  
7 - Babs Seed  
8 - Apple Bloom  
9 - Big MacIntosh  
10 - Applejack  
11 - Granny Smith  
12 - Apple Bumpkin (< show name; toy name: Apple Dazzle)  
13 - Red Delicious  
14 - Red-Gala (< show name; toy name: Crimson Gala)  
15 - Apple Cobbler  
16 - fan name: Marmalade Jalapeno Popette. (A pony with the exact same looks but a different cutie mark is Orange Wafer.)  
17 - (Uncle) Apple Strudel  
18 -  
19 - Derpibooru fan name: Candy Apple as of >>191876  
20 - Braeburn  
21 -  
22 - Derpibooru fan name: Apple Turnover (as per >>194084) or Apple Brown Betty (>>206840)  
23 - Applesauce  
24 - Apple Rose (cousin of Granny Smith)  
25 - Aunt Orange  
26 - Uncle Orange (toy name: Mosely Orange)  
27 - unnamed, fan name is Apple Tarty  
28 - unconfirmed but likely Golden Delicious (based on cutie mark & the list of names from s01e01)  
29 - Pink Lady  
30 - Apple Dumpling (? - based on credits)  
31 - Derpibooru fan names: Red Hickory and Bucky. (there is some confusion as to maybe he is Half Baked Apple or maybe Caramel Apple from the official list.)  
32 - Apple Leaves (mother of 8 including a baby named Apple Tart)  
33 - Half Baked Apple  
34-  
35 -  
36 - Apple Fritter (>show name; toy name: Apple Stars; +possible bf? Meadow Song also seen in the episode)  
37 - Apple Pie  
38 - unconfirmed but likely Apple Cinnamon Crisp (based on cutie mark & the list of names from s01e01)  
39 - Hayseed Turnip Truck
 
Not pictured above:  
Caramel Apple (Carrot Top cutie mark swap), Peachy Sweet (from “Over A Barrel”),  
Apple Cider,  
?