Immigration is a tool for After Effects that rapidly gathers sequences within a directory and can import several at a time. It also has a history and versioning tool which is far more intelligent than the After Effects native file browser, which is really just the OS browser. This is even more sophisticated than the sequence gathering tools built into just about any app out there that deals with sequences, Nuke, Fusion etc. It really is just Adobe who refuse to get on the band wagon when it comes to gathering sequences of images to a single line item.
I have been using Adobe products since about the time of the first Creative Suites, and After Effects since about version CS3. It has always struck me as strange that After Effects, Premiere and Photoshop (in animation mode) do not even offer a 'gather sequences' preference. This simple UI feature is invaluable for any video editors, compositors and 3D artists dealing with what can be hundreds of passes. How this persists to be the case 20-30 years into development remains a mystery to me, but it seems the good people at Adobe are oblivious to the issue.
I'm going to try to speak to Adobe directly to see if we can get this in the 2018 release of CC. In the interim this tool can save your bacon if you do a lot of this kind of thing. At $45 USD it is a bittersweet recommendation - sweet because it works very well, and bitter because that's a very high price to ask for such a simple feature, that let's face it, really should be built into the vanilla app.
I leave such judgments to you though, I hope this proves useful.