Hi , I have updated the Crawler.
Now you can use followNext(), followPrev() and followBack().
The API provides also a new way to instanciate de crawler by using:
StellarCrawler::newInstance($publicKey, $isPublicNetwork);
or
StellarCrawler::newInstanceWithServer($publicKey, $horizonServer);
The documentation has been updated and you can now use Composer or the phar file to include the library to your projects.
Thank you very much for your remarks.