I've been assembling a list of these lately for a book that I'm working on. (http://startingandsustaining.com http://startingandsustaining.com) Some of the cat

I've been assembling a list of these lately for a book that I'm working on. (http://startingandsustaining.com http://startingandsustaining.com) Some of the categories are fairly loose as some apps don't fit nicely into categorical buckets, but hopefully this is a helpful list. --Browser/Email Testing BrowserStack (http://www.browserstack.com http://www.browserstack.com) Litmus (http://litmus.com http://litmus.com) --Bug/Issue Tracking BugHerd (http://bugherd.com http://bugherd.com) Lighthouse (http://lighthouseapp.com http://lighthouseapp.com) Sifter (http://sifterapp.com http://sifterapp.com) (Disclaimer: I built this.) --Planning & Project Management Sprintly (http://sprint.ly http://sprint.ly) Podio (https://podio.com https://podio.com) Flow (http://www.getflow.com http://www.getflow.com) Interstate (http://interstateapp.com http://interstateapp.com) Basecamp (http://basecamp.com http://basecamp.com) Apollo (http://www.apollohq.com http://www.apollohq.com) Pivotal (http://www.pivotaltracker.com http://www.pivotaltracker.com) Asana (http://www.asana.com http://www.asana.com) Trello (https://trello.com https://trello.com) Blossom (https://www.blossom.io https://www.blossom.io) Trajectory (https://www.apptrajectory.com https://www.apptrajectory.com) --Business & Traffic Analytics KissMetrics (http://kissmetrics.com http://kissmetrics.com) MixPanel (http://mixpanel.com http://mixpanel.com) DigMyData (http://digmydata.com http://digmydata.com) --Continuous Integration / Code Quality Travis (https://travis-ci.org https://travis-ci.org) Circle (http://circleci.com http://circleci.com) CodeClimate (http://codeclimate.com http://codeclimate.com) Sempaphore (https://semaphoreapp.com https://semaphoreapp.com) --Dashboards Ducksboard (http://ducksboard.com http://ducksboard.com) Geckoboard (http://www.geckoboard.com http://www.geckoboard.com) Instrumental (https://instrumentalapp.com https://instrumentalapp.com) --Error/Exception Handling Sentry (https://getsentry.com https://getsentry.com) Coalmine (https://www.getcoalmine.com https://www.getcoalmine.com) HoneyBadger (https://www.honeybadger.io https://www.honeybadger.io) BugSnag (https://bugsnag.com https://bugsnag.com) Raygun (http://raygun.io http://raygun.io) --Log Monitoring Loggly (http://loggly.com http://loggly.com) Papertrail (https://papertrailapp.com https://papertrailapp.com) LogEntries (https://logentries.com https://logentries.com) --Billing & Payment Processing Braintree (https://www.braintreepayments.com https://www.braintreepayments.com) Stripe (http://stripe.com http://stripe.com) Pin (http://pin.net.au http://pin.net.au) PayMill (http://paymill.com http://paymill.com) Recurly (http://recurly.com http://recurly.com) Chargify (http://chargify.com http://chargify.com) Spreedly (http://spreedly.com http://spreedly.com) Spreedly Core (https://core.spreedly.com https://core.spreedly.com) --Support/Help Desks Desk (http://desk.com http://desk.com) HelpScout (http://helpscout.net http://helpscout.net) ZenDesk (http://zendesk.com http://zendesk.com) Groove (http://groovehq.com http://groovehq.com) Intercom (http://intercom.io http://intercom.io) Tender (http://tenderapp.com http://tenderapp.com) --Transactional Email Postmark (https://postmarkapp.com https://postmarkapp.com) Mandril (http://mandrill.com http://mandrill.com) MailGun (http://www.mailgun.com http://www.mailgun.com) SendGrid (http://sendgrid.com http://sendgrid.com) CloudSMTP (http://www.cloudsmtp.com http://www.cloudsmtp.com) CritSend (http://www.critsend.com http://www.critsend.com) Postage (http://postageapp.com http://postageapp.com) --Email Collection/Landing Page Apps Launchrock (http://launchrock.com http://launchrock.com) Unbounce (http://unbounce.com http://unbounce.com) KickoffLabs (http://www.kickofflabs.com http://www.kickofflabs.com) Launch Effect (http://launcheffectapp.com http://launcheffectapp.com) Prefinery (https://www.prefinery.com https://www.prefinery.com) LaunchGator (http://launch.deskgator.com http://launch.deskgator.com)