Long-Term Stellar Variability with Kepler FFIs
We have developed the f3 photometry package for developing light curves from the Kepler Full Frame Images, a set of 53 images obtained approximately monthly during the primary Kepler mission. We applied this package to a collection of Sun-like stars to search for signatures of magnetic activity.

You can find a preprint of the paper here. Please cite this paper (ADS link here) if you use these data or the f3 package.

We targeted a total of 3,845 stars in our survey. Light curves for all of these stars are included as a tar file which can be downloaded right here or for an individual star here. The data come with five columns: time (taken directly from the Kepler FFI FITS headers), calculated flux, a "normalized" flux accounting for the starspot level observed in the long cadence data, and the inferred x- and y-positions of the centroid of light in the aperture.

Interesting Stars:
A total of 463 stars were found to have non-constant flux over the duration of the Kepler mission. These stars are listed in Table 1 of the paper, which is a machine readable table. This table can be found in its entirety at this link, as well as in the source code available on the arXiv and (eventually) on the journal website.

A total of 28 stars have what appear to be complete cycles, whether they represent an entire cycle or a short-period cycle on top of a longer cycle for that star. These are listed in Table 2 of the paper, which is reproduced here.