Observing and modifying object-oriented programs often means interacting with objects. At runtime, it can be a complex task to identify those objects due to the live state of the program. Some objects may exist for only a very limited period of time, others can be hardly reachable because they are never stored in variables. To address this problem we present Collectors. They are dedicated objects which can collect objects of interest at runtime and present them to the developer. Collectors are non-intrusive, removable code instrumentations. They can be dynamically specified and injected at runtime. They expose an API to allow their specification and the access to the collected objects. In this paper, we present an implementation of Collectors in Pharo, a Smalltalk dialect. We enrich the Pharo programming and debugging environment with tools that support the Collectors API. We illustrate the use of these API and tools through the collection and the logging of specific objects in a running IOT application.