pgweb is described as 'Web-based cross-platform client for PostgreSQL databases'. There are six alternatives to pgweb for a variety of platforms, including Mac, Windows, Linux, Online / Web-based and Self-Hosted solutions. The best alternative is pgAdmin, which is both free and Open Source. Other great apps like pgweb are Adminer (Free, Open Source), Postico (Freemium), Phppgadmin (Free, Open Source) and omnidb (Free, Open Source).
Adminer (formerly phpMinAdmin) is a full-featured database management tool written in PHP. Conversely to phpMyAdmin, it consist of a single file ready to deploy to the target server. Adminer is available for MySQL, PostgreSQL, SQLite, MS SQL and Oracle
PostgreSQL is an absurdly powerful database, but there's no reason why using it should require an advanced degree in relational theory. Postico provides an easy to use interface, making Postgres more accessible for newcomers and specialists alike.
phpLiteAdmin is a web-based SQLite database admin tool written in PHP with support for SQLite2 and SQLite3. Following in the spirit of the flat-file system used by SQLite, phpLiteAdmin consists of a single source file, phpliteadmin.