Some basics that your application could benefit from.

A Net::HTTP wrapper

simple-images-downloader allows to download images from a file containing list of urls to those images.

Use a given JSON and fields names to generate a CSV.

Simple JSON Schema validator. Supports draft 7 partial, based on https://github.com/davishmcclurg/json_schemer

Simple ImageMagick Wrapper.

Simple FFI wrapper for Mapnik

SimpleMigrator provides basic programmatic migrations for Sequel

Redis-based mutex library for using with sidekiq jobs and batches.

Simple objects for Ruby

Rails data batch migrations made easy.

Simple Profiler

A simple rack for log information from environment.

Range validator for any Range model fields

Simple ORM backed with redis store

SimplerEnum provides Rails like enumerated type

Simple Ruby Service is a lightweight framework for creating Services and Service Objects (SOs) in Ruby. The framework makes Services and SOs look and feel like ActiveModels, complete with: 1. validations and robust error handling; 2. workflows and method chaining; and 3. consistent interfaces. Additionally, Simple Ruby Service Objects can stand in for Procs, wherever Procs are expected (via ducktyping).

Library was built on top of nokogiri, parallel and httparty gems that do most of the work

Simple helper to create 'show' pages easily.

Minimalistic templates engine