When comparing OmniDB vs QueryPie, the Slant community recommends OmniDB for most people. In the question“What are the best GUI tools for PostgreSQL on Windows?” OmniDB is ranked 4th while QueryPie is ranked 7th.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Open source and actively developed
Pro PL/pgSQL Debugger
Pro Web-based, can be run locally or deployed on server
OmniDB is web-based and works similarly to pgAdmin 4. You can run the web server locally or deploy it on a server, and connect to it through a web browser.
Pro Multi-database
Supports PostgreSQL, Oracle, MySQL and MariaDB, with support in the pipeline for Firebird, SQLite, SQL Server and DB2.
Pro Simple and intuitive interface for everyone.
An easy-to-discover tree panel to classify features/objects on left (with context menus if you don't know what you're doing). Tabs panels for ins and outs on right. That's it.
Pro OmniDB has 2ndQuadrant as its main sponsor
Pro Clean and pretty UI/UX
The default color is dark and comfortable for the eyes.
Pro Multiple Query Tabs!
The multi-tab and multi-SQL-runs are great. It's always good to be able to compare results in one window instead of having to go through and re-run stuff.
Pro Fast Auto-complete
Pro Multiple Databases
They only support 2 at the moment (MySQL and MariaDB) but their social site says they'll be updating with more DBMSes in the near future which is pretty nice because I hate learning new GUIs~
Pro Cross-Platform
Not sure about Linux but it works on Windows and Mac just fine!
Pro Free!
Cons
Con Requires creating an account
Requiring an account is rare on SQL IDEs...