Twilight's fears over becoming a princess convince her to attempt a spell to glimpse the future. Unfortunately, she ends up doing a bit more than glimpsing; the spell turned out to be permanent, meaning she never returned back to her own time, and therefore didn't exist for ten full years.

Her absence caused a fall-apart of the elements of harmony, and Twilight is horrified to see how they've changed without her. She doesn't know how to teleport back, so she instead tries desperately to figure out what happened and piece everyone's lives back together.

Apple Bloom is left alone and bored while Scootaloo is learning to fly and Sweetie Belle is learning magic. Applejack sees that her sister feels less special because she's an earth pony, and decides to get Pinkie Pie's help in teaching the filly about why earth ponies are so important.

The sequel to The AppleDash Project, but that was episodic you can jump right in! All you need to know is:

Applejack and Rainbow Dash have been together for more than a year now. Their relationship has blossomed through Discord, a changeling army, and a whole hoof full of crazy situations and dumb mistakes. They've managed to form a partnership and learned to work out their problems together, not an easy lesson for two tough, stubborn ponies.

But now Rainbow Dash is convinced that their lives are getting boring, and if there's one thing Dash doesn't like, it's boring. So Dash has set out to make her relationship with Applejack more interesting. . . and AJ's not so sure she likes that sound of that.

From the original AppleDash Project:
The AppleDash Project is a series of short fics attached to various episodes, detailing a relationship between Rainbow Dash and Applejack behind the scenes. The stories take place sometime during or shortly after the indicated episode.

This is not meant to start shipping wars, argue that AppleDash is canon, or offend other shippers. In fact, if you like the idea I encourage you to try it with other ships!

Teen rating means that there may be talking about sex, but nothing on screen. Expect sitcom-like innuendo.

Seasons one and two are now complete! Season three is being continued in The AppleDash Project: Wherever Life Takes Us.

The AppleDash project is a series of short fics attached to various episodes, detailing a relationship between Rainbow Dash and Applejack behind the scenes. The stories take place sometime during or shortly after the indicated episode.

This is not meant to start shipping wars, argue that AppleDash is canon, or offend other shippers. In fact, if you like the idea I encourage you to try it with other ships!

Teen rating means that there may be talking about sex, and there is one line of dialogue that takes place during intimate relations, but it's warned for and skippable. Nothing sexual is described.

Twilight discovers a book about the history of the Apple family, but it's missing some information. While it tells all about Granny Smith's life, there's no mention of a husband or any children. Twilight goes to Sweet Apple Acres to fill in the gaps and gets a lesson about what it means to be a family.

Applejack and Big Macintosh both have dates for the evening, but Apple Bloom isn't about to let them out of the house until her curiosity is satisfied. . .

This could be a while.

(If you are against fillyfooling or coltcuddling, this is not the fic for you.)

Twilight Sparkle was thrilled to find her place as Princess of Friendship. But what is a Princess of Friendship without her friends? When Applejack comes to her to have an important conversation, Twilight is reminded that some of her friends have places of their own.

Part of the "All In" minific writeoff.

As the Grand Galloping Gala draws near, Rainbow Dash is set to impress with the dress Rarity had designed. She is met with approval from all but one pony.

Takes place during the episode of "Make New Friends but Keep Discord"
One Shot fic

Scootaloo has never really cared much for Pinkie Pie, and she definitely doesn’t like the way Pinkie calls her hero “Dashie.” But for some strange reason, Pinkie seems fixated on her and insistent on meddling in Scootaloo’s life. Whether Scootaloo likes it or not.

Now with TV Tropes page!

Twilight Sparkle realizes that Rainbow Dash has been keeping a secret from her ever since the Mare Do Well incident. When she goes to confront her about it, she finds out more than she bargained for. And then Twilight reveals that she's been keeping something from her friends ever since the Royal Wedding. Now everything is out there; harsh words have been spoken and a once strong friendship hangs in the balance.